rebreather

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The advantages of d
­ iving
on a rebreather are many:
longer bottom times,
fewer bubbles to scare
your favorite marine
life, and warm, moist
­breathing gas. What are
you waiting for?
3
Demonstrate Discipline
To dive these units safely, careful
prep and post-dive care is required for
each and every dive. “Although recreational rebreather diving has come of age,
there are still crucial things to remember,” says Weber. “The most important
is being disciplined. It’s not the same as
just throwing together a tank, BC and
reg and hopping in the water.” Before
and after each dive, you’ll get your tank
filled with an analyzed nitrox mixture,
insert the pre-pack scrubber canister,
assemble the unit, perform all predive
checks — such as positive pressure, negative pressure, flow rate, bypass regulator
operation, relief valve pressure and leak
checks — and clean and disinfect the unit
after the dive.
4
Figure Out Your Budget
Courses usually cost between $700
and $1,500. The personal dive gear you
need includes a mask, fins and snorkel,
reel or finger spool, SMB or lift bag,
READY FOR A REBREATHER?
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Do a Training and Skills Check
PADI requires that students have
both Open Water Diver and Enriched Air
Diver certifications, a minimum of 25
logged dives and be at least 18 years old.
Weber says having a good understanding
of the basic principles of gas-exchange
physics, such as PPO2 (partial pressure
of oxygen) and FO2 (fraction of oxygen),
and excellent buoyancy skills will make
the learning process a bit easier.
Make a Commitment to Learn
You must be ready to understand
how a rebreather system works, the
physics and physiology associated with
this diving, and how to put the unit
together, test and clean it. The course
spans roughly four days and includes
nine dives. Specific training is required
for each model. “Each manufacturer
builds its units differently,” says Weber,
“so each unit is different in terms of
assembly, prep, emergency procedures,
post-trip prep and maintenance.” You
can rent a unit for the course, and Weber
says that “once you learn how to dive one
rebreather, you can get an additional unit
qualification on another unit.”
FROM TOP: JASON BROWN; COURTESY HOLLIS. OPPOSITE: TANYA G. BURNETT
1
2
Experience the Rewards
Rebreathers offer extended dive
duration, longer no-decompression
times, reduced weight, a warmer gas
exchange and the ability to get closer to
marine life. “I can get up close and personal with most things that live in the
sea with my rebreather, where on open
circuit I just scare everything away,” says
Weber. “I’ve been able to get very close
to goliath groupers and ocean sunfish
on my rebreather, something just not
really possible on open circuit.” Diving
sans bubbles inside a wreck lessens
the amount of debris that is knocked
down from the ceiling. “If you’re the
type who can be disciplined enough, a
rebreather can open doors to encounters
that you can only dream of,” Weber says.
Understanding how a rebreather works can help you
choose which one to buy
BY TA N YA G . BU R N E T T
is the same thing — you’ve got an
unrestricted pass to get up close and personal with all kinds of ocean life. With no
bubbles or sounds to disturb them, you
are accepted as one of them.”
5
What’s Your Type?
What you need to know before signing up for recreational rebreather training
If you associate rebreathers only with
technical diving, it’s time to take a
look at the new Type R, or recreational,
rebreathers, such as the Hollis Explorer
Sport (shown in the photo at right). These
units are lightweight, easy to transport
and have sophisticated yet simple electronics, plus they let you experience
things you never imagined possible.
“Imagine having an all-access backstage pass to all the hot Hollywood parties
where all the stars know you and love
you,” says James Weber, a Semi-Closed
Circuit Rebreather and Fully Closed
Circuit Rebreather instructor with
PADI Five Star Force-E Scuba, ­R iviera
Beach, Florida. “Diving a rebreather
bail-out tank and regulator, and an
­exposure suit adequate for the openwater environment. Added costs include
the nitrox fills, scrubber material, and
the rental or purchase of the rebreather.
There are three primary categories of rebreathers: Oxygen, Semi-Closed Circuit (SCR) and
Fully Closed Circuit Rebreathers (CCR). These systems vary in the manner in which gas
is added or replenished, but all rebreathers must scrub out the carbon dioxide from the
breathing gas.
Hollis Explorer Sport
The compact and lightweight Hollis
Explorer Sport’s unique design uses a
single cylinder of nitrox, ranging from
32 to 40 percent, and the electronics
feature a predive diagnostic that runs
with just a few prompts to the diver. It’s
electronically controlled to automatically analyze the gas mixture, and will
adjust accordingly to achieve an optimal balance of PPO2 and dive time.
The unit uses a refillable absorbent
cartridge, has optional CO2 tracking
and offers a maximum dive time of
two hours. MSRP: $4,995.95;
optional CO2 monitor kit available
for $495.95
Going with
the Flow
Diving bubble-free with
the Hollis Explorer eSCR
on the German WWI
cruiser Karlsruhe
Scapa Flow in the Orkney Islands
— off the windswept northern tip of
Scotland — is a wreck-diving mecca
thanks to the remains of German
World War I battleships and cruisers
lying on the seabed.
This year, I dived the wrecks using
a Hollis Explorer eSCR rebreather. The
final dive of the week really showed
the true beauty of the unit.
The SMS Karlsruhe is one of three
cruisers in Scapa Flow, and there is
plenty to see along its 367-foot length,
most notably an intact stern, complete with anchor, 5.9-inch deck guns
and a dramatic bow. With the deepest sections in 82 feet of water, and
its highest points reaching 45 feet,
even single-tank divers have plenty
of bottom time, but on the Explorer, I
completed 46 minutes on the seafloor
before I got near my no-deco limits,
and as soon as I ascended to around
55 or 60 feet, my handset displayed
that I had another 48 minutes before
I needed to surface. That was a total
possible no-deco dive time of over 90
minutes — and all on a 5-liter tank of
40 percent nitrox and small scrubber
of sofnalime. Plus, breathing warm
gas through the loop helped stave
off the cold of the 46-degree water,
and with massively reduced bubbles,
I could get close to any marine life I
­encountered. — Sport Diver EMEA
­Editor Mark Evans
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